The present invention relates to a flashing assembly for building walls, storefronts, curtain walls, windows, and the like.
Flashing assemblies for storefronts and other building areas having large windows are known in the prior art. However, the earlier flashing assemblies suffer from one or more serious disadvantages making them less than entirely suitable for their intended purpose.
Flashing assemblies generally include a sill flashing or flashing plate for attachment to a sill, and a sill horizontal for supporting a window. The sill flashing and the sill horizontal are preferably both made from aluminum alloy extrusions. The sill flashing is attached to a wood sill or other substrate by through fasteners, generally metal screws or bolts.
A window frame including a sill horizontal is set onto the sill flashing after it is attached to the substrate. Then holes are drilled through the sill horizontal and into the sill flashing. Fasteners are then installed through the sill horizontal in order to anchor the window frame to the substrate.
In order to minimize the potential for leaks, the installer must pump a sealant through the hole in the sill horizontal and hope to hit the area of the hole in the sill flashing. A sealant is then applied to the fastener, and the fastener is installed through both holes. Because of the possibility of leaks occurring in assemblies having through fasteners penetrating both the sill horizontal and sill flashing, there still remains a need for a flashing assembly eliminating those undesirable features.
A principal objective of the present invention is to provide a flashing assembly having a sill horizontal attached to sill flashing without any through fasteners.
A related objective of the invention is to provide a flashing assembly wherein blind seals are avoided.
Another objective of the invention is to provide a flashing assembly that can be installed easily.
A further objective of the invention is to provide a flashing assembly having improved water pressure performance. The flashing assembly of the invention also has improved structural performance so that its resistance to wind damage is enhanced.
Additional objectives and advantages of our invention will become apparent to persons skilled in the art from the following detailed description of a particularly preferred embodiment.
In accordance with the present invention there is provided a flashing assembly for building walls, storefronts, curtain walls, windows and the like.
The flashing assembly of our invention includes a sill horizontal, a sill flashing, and at least one sill clip for joining the sill horizontal to the sill flashing. The sill horizontal, sill flashing, and sill clip may be manufactured from various metals, fiber reinforced plastics, wood, or other materials capable of being shaped into a desired configuration. All three principal components are preferably made of metal and in a particularly preferred embodiment they all include aluminum alloy extrusions.
The sill horizontal is preferably part of a window frame that also includes laterally spaced first and second window mullions joined to opposed, laterally spaced, first and second lateral end portions of the sill horizontal. The frame also includes a top rail spaced upwardly of the sill horizontal. The mullions and the top rail preferably include aluminum alloy extrusions. The window frame circumscribes a window, preferably a double glazed or monolithic (single glazed) glass window.
A preferred sill horizontal includes a sill top wall for supporting a window pane, a sill face attached to the sill top wall and extending downwardly therefrom, a forwardly extending back flange attached to the sill face, a sill front wall attached to the sill top wall and extending downwardly therefrom, and a rearwardly extending front flange attached to the sill front wall. The sill horizontal is mechanically attached to vertically extending frame members such as mullions or jambs. For example the sill horizontal may be attached to a mullion by a metal clip, by metal screws held in a spline formed integrally with the sill horizontal, or by welding.
A preferred sill flashing includes a front wall, a front web attached to the front wall, and a channel connected with the front web and extending downwardly thereof. The channel is defined by a channel front wall connected with the front web, a channel rear wall, and a channel bottom wall extending between the channel front wall and rear wall.
In a particularly preferred embodiment the sill horizontal and sill flashing each comprise an aluminum alloy extrusion. When desired, both structures may also include a thermal isolator or thermal break for reducing heat transfer. The thermal isolator includes an insulating plastic material such as polyurethane (PU), polyvinyl chloride (PVC) or acrylonitrile-butadiene-styrene (ABS).
The thermal isolator is typically manufactured by the xe2x80x9cpour/debridgexe2x80x9d method, described in greater detail in U.S. Pat. Nos. 3,204,324 and 4,619,097, incorporated herein by reference to the extent consistent with the present invention. The method involves pouring a quantity of a thermally insulating plastic resin into an open groove in the extrusion. The extrusion initially includes a metal bar or bridge interconnecting front and rear parts of the extrusion. When the plastic resin cures into a solid, rigid state and the metal bridge is removed, the resin forms a connector between the front and rear parts. The two metal parts remain joined together even though the bridge is gone. Thus, a composite structure is formed in which the two aluminum alloy parts are thermally insulated from one another by the plastic thermal break material.
It is desirable to provide a mechanical interlock between the two aluminum parts and the plastic thermal break material so that the structural integrity of the composite is not entirely dependent upon adhesive bonding between the plastic and aluminum elements. Accordingly, projections are formed in the extrusions extending inwardly of the groove holding the plastic insulating material. The projections prevent displacement of the aluminum parts with respect to the plastic thermal break material in response to tensile and shear forces.
The sill clip of the invention may be metal or plastic and is preferably an aluminum alloy extrusion. A preferred flashing assembly includes laterally spaced, first and second sill clips adjacent opposed, laterally. spaced first and second lateral end portions of the sill horizontal. The sill clips preferably have a length of only a few inches whereas lengths of the sill horizontal and sill flashing generally range between a few feet and several feet. A particularly preferred sill clip has a length of about 3 inches (7.5 cm).
The sill clip includes a shelf and at least one foot extending downwardly from the shelf The shelf includes a front edge portion for supporting the front flange of the sill horizontal and a back edge portion for supporting the back flange of the sill horizontal. The sill clip also preferably includes a front foot extending downwardly into the channel of the sill flashing adjacent the channel front wall and a rear foot extending downwardly into the channel adjacent the channel rear wall
The sill clip is preferably interlocked with the sill horizontal and the sill flashing. In a particularly preferred embodiment the front flange of the sill horizontal includes a rearwardly extending front tab for insertion into a front groove defined by the sill clip shelf. The back flange of the sill horizontal includes a forwardly extending back tab for insertion into a back groove defined by the sill clip shelf A front foot on the sill clip includes a forwardly extending projection and the channel front wall supports a web having a portion extending rearwardly over the projection. The sill flashing preferably includes a sill face adjacent a lower portion of the sill back wall on the sill horizontal.
The sill horizontal has opposed, laterally spaced first and second end portions. The first and second end portions are attached to vertically extending mullions, either by mechanical means or by welding. Preferably, both end portions include screw splines for attaching the sill horizontal to a mullion with metal screw fasteners. Optionally, the sill clip may also include laterally opening screw splines for connecting the clip to a mullion with metal screw fasteners.
The flashing assembly allows the resultant end reaction from wind loading on a building wall to be transferred to the sill flashing through the sill clip. The resultant end reaction is distributed through the bearing contact of the mullion and the downwardly extending J-shaped feet of the sill clips into the channel of the sill flashing. Resistance to wind damage is improved by converting the resultant end reaction into shear stress rather than bending.